The present invention relates to a dental drilling assembly and, more particularly, to a dental triple arm drilling apparatus which can be adapted for operation with both a small and a large size pulley disposed on the motor of the drilling assembly.
Motors which are utilized for operating drilling devices, for example, triple arm dental drilling assemblies, are provided with two size pulleys, that is, a small pulley and a large pulley which is attached directly to the motor. Thus, in the prior art, when it is desired to use the large pulley attached to the motor to achieve a slower rotational speed, it was necessary to use a triple arm drilling assembly which contained a large space between the wheels so that the drilling assembly was made compatible with the large pulley of the motor. On the other hand, when the small pulley of the motor was utilized in order to achieve a higher operational speed, it was necessary to replace the triple arm drilling assembly with a different drilling assembly which provided a narrow space between the side wheels thereof so that the assembly was compatible with the smaller pulley of the motor. The need to change the arms of the drilling assemblies to correspond to the size of the pulley utilized on the motor takes a long period of time and, thus, is very inconvenient.